Ammunition magazine and resilient member

ABSTRACT

A magazine for storing and feeding ammunition cartridges to a small arms weapon which comprises a casing, a floor plate, a follower, and a magazine spring inside the casing. The magazine spring may comprise a first end connected to the follower, a second end connected to the floor plate, and a plurality of coils. Each of the plurality of coils may include a first segment having a first radius, a second segment having a first length adjoining the first segment, a third segment having a second radius adjoining the second segment, the second radius being greater than the first radius, and a fourth segment having a second length adjoining the third segment, the second length being approximately equal to the first length.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of application No. 29/472,057filed Nov. 7, 2013. This application claims the benefit of provisionalApplication No. 61/912,521 filed Dec. 5, 2013. The disclosure of each ofthese applications is incorporated by reference herein in theirentirety.

FIELD OF THE INVENTION

The present invention generally relates to a method for storing andfeeding ammunition cartridges to a small arms weapon. More particularly,this invention relates to an ammunition magazine for a small armsweapon. This invention also relates to a resilient biasing member formoving ammunition cartridges through a magazine.

BACKGROUND

Reliable delivery of ammunition from an external supply into a firearmchamber is an important aspect of effective firearm operations. Thestructure and capacity of the external supply of ammunition may affectthe consistency of ammunition delivery. Additionally, the ability of theexternal supply to be detached from the firearm, reloaded withammunition, and then reused with the firearm may enhance theeffectiveness of firearm operations. Although ammunition magazines(e.g., STANAG or STANAG-compatible box magazines) are known, someammunition magazines may lack durability or tend to malfunction.Accordingly, a need exists for new ammunition storage and feedingdevices.

SUMMARY

Hence, the present invention is directed to an ammunition magazine forstoring and feeding ammunition cartridges to a firearm. The presentinvention is also directed to a magazine spring.

One aspect of the present invention relates to a magazine for storingand feeding ammunition cartridges to a small arms weapon. The magazinemay include a casing which comprises an upper end and a lower end, afloor plate situated near the lower end, a follower adjacent the floorplate, and a magazine spring inside the casing. The magazine spring maycomprise a first end connected to the follower, a second end connectedto the floor plate, and a plurality of coils. Each of the plurality ofcoils may include a first segment having a first radius, a secondsegment having a first length adjoining the first segment, a thirdsegment having a second radius adjoining the second segment, the secondradius being greater than the first radius, and a fourth segment havinga second length adjoining the third segment, the second length beingapproximately equal to the first length. The second radius divided bythe first radius may define a coil ratio. Preferably, the coil ratio maybe between approximately 1.1 and approximately 1.5.

In another aspect, the magazine spring may be preloaded for a force ofapproximately 15 N at a reference length of approximately 180 mm. Themagazine spring further may have a solid height that is less than orequal to approximately 25 mm. Moreover, the second radius may beapproximately 8.1 mm and the first radius may be approximately 6.5 mm.The magazine spring may be formed from a round wire. The round wire mayhave an outer diameter of approximately 1.5 mm and may be music wire perASTM A228.

In another aspect, the magazine spring may be preloaded for a force ofapproximately 15 N at a reference length of approximately 75 mm. Themagazine spring may have a solid height less than or equal toapproximately 20 mm. The second radius may be approximately 8.1 mm andthe first radius may be approximately 6.1 mm. The magazine spring may beformed from a round wire. The round wire may have an outer diameter ofapproximately 1.5 mm and may be music wire per ASTM A228

In another aspect, the magazine casing may be configured and dimensionedto store a plurality of ammunition cartridges for a small arms weapon.For example, the casing may be configured and dimensioned to store 30 orfewer ammunition cartridges. In another example, the casing may beconfigured and dimensioned to store 10 or fewer ammunition cartridges.The casing may be configured and dimensioned to store 5.56×45 mm NATOcartridges or .223 Remington cartridges.

Another aspect of the present invention relates to a magazine spring foran ammunition magazine for a small arms weapon. The magazine spring mayinclude a wire which comprises a plurality of coils. Each of theplurality of coils may include a first segment having a first radius, asecond segment having a first length adjoining the first segment, athird segment having a second radius adjoining the second segment, thesecond radius being greater than the first radius, and a fourth segmenthaving a second length adjoining the third segment, the second lengthbeing approximately equal to the first length. The second radius furthermay be divided by the first radius to define a coil ratio, and the coilratio may be at least about 1.05.

In another aspect, the coil ratio may be less than about 3. Preferably,the coil ratio may range from approximately 1.10 to approximately 1.50.More preferably, the coil ratio may range from approximately 1.20 toapproximately 1.35. In an exemplary embodiment of the invention, thecoil ratio is approximately 1.25. In another exemplary embodiment, thecoil ratio is approximately 1.32.

In another aspect, the wire may have a preloaded force of approximately15 N for a reference length that ranges from approximately 75 mm toapproximately 180 mm.

In another aspect, the second radius may be between approximately 7.8 mmand 8.4 mm.

In a preferred embodiment, the first radius may be between approximately5.8 mm and approximately 6.4 mm.

In another preferred embodiment, the first radius may be betweenapproximately 6.2 mm and approximately 6.4 mm.

In another aspect, each of the plurality of coils may have a maximumouter dimension between approximately 49.2 mm and approximately 49.8 mm.

In another aspect, the wire may be a round wire, a stranded wire, or ashaped wire. The shaped wire may be is selected from one of the groupconsisting of square, rectangular, keystone, oval, elliptical, halfround, or D-shaped.

In another aspect, the wire may be carbon steel. For example, the wiremay be music wire.

In another aspect, the wire may be alloy steel. For example, the wiremay be chrome silicon.

DESCRIPTION OF THE DRAWINGS

In the accompanying drawings, which form a part of the specification andare to be read in conjunction therewith and in which like referencenumerals (or designations) are used to indicate like parts in thevarious views:

FIG. 1 is a perspective view of an exemplary embodiment of an ammunitionmagazine in accordance with the present invention;

FIG. 2 is top view of the magazine of FIG. 1;

FIG. 3 is a perspective view of the magazine of FIG. 1 loaded in anAR-15 type firearm;

FIG. 4 is another perspective view of the magazine of FIG. 1, themagazine being loaded with ammunition cartridges;

FIG. 5 is a partial perspective view of the casing of the magazine ofFIG. 1;

FIG. 6 is an exploded view of the magazine of FIG. 1, along with acartridge that may be stored in the magazine;

FIG. 7 is a cross-sectional view of the magazine of FIG. 1, along line7-7, where the magazine is empty and the follower and spring are in anextended configuration;

FIG. 8 is a partial cross-sectional view of the magazine of FIG. 1,along line 7-7, where the magazine is partially loaded with ammunitioncartridges and the follower and spring are in a depressed configuration;

FIG. 9 is a partial cross-sectional view of the magazine of FIG. 1,along line 7-7, where the magazine is fully loaded with ammunitioncartridges and the follower and spring are in a nearly fully depressedconfiguration;

FIG. 9 a is a partial cross-sectional view of another embodiment of themagazine of FIG. 1, along line 7-7, where the magazine is fully loadedwith ammunition cartridges and the follower and spring are in a fullydepressed configuration;

FIG. 9 b is a partial cross-sectional view of yet another embodiment ofthe magazine of FIG. 1, along line 7-7, where the magazine is fullyloaded with ammunition cartridges and the follower and spring are in afully depressed configuration;

FIG. 10 is a partial cross-sectional view of the magazine of FIG. 8,along line 10-10;

FIG. 11 is a perspective view of the follower of FIG. 1;

FIG. 12 is a cross-sectional view of the magazine of FIG. 7, along line12-12;

FIG. 13 is a cross-sectional view of the magazine of FIG. 7, along line13-13;

FIG. 14 is a bottom, partial perspective view of the follower and springof FIG. 6;

FIG. 15 is a perspective view of the floor plate of FIG. 6;

FIG. 16 is a cross-sectional view of the magazine of FIG. 7, along line16-16;

FIG. 17 is a partially exploded view of the bottom end of the magazineof FIG. 1;

FIG. 18 is a perspective view of the base of FIG. 6;

FIG. 19 is a partial cross-sectional perspective view of the magazinecasing of FIG. 8;

FIG. 20 is another partial cross-sectional perspective view of themagazine casing of FIG. 8;

FIG. 21 is a cross-sectional view of the magazine casing of FIG. 19,along line 21-21;

FIG. 22A is a side view of an exemplary design for the magazine springof FIG. 1;

FIG. 22B is a front view of the magazine spring of FIG. 22A;

FIG. 22C is a perspective view of the magazine spring of FIG. 22A;

FIG. 22D is a top view of the magazine spring of FIG. 22A;

FIG. 22E is a cross-sectional view of the spring of FIG. 22A, along line22E-22E;

FIG. 22F is a cross-sectional view of the spring of FIG. 22A, along line22F-22F;

FIG. 23 is a schematic depiction of the effect of the ammunition guidesurfaces and multi-faceted block on the position of six ammunitioncartridges disposed in the magazine of FIG. 1;

FIG. 24 is a cross-sectional view of the FIG. 23, along line 24-24;

FIG. 25 is a cross-sectional view of the FIG. 23, along line 25-25;

FIG. 26 is a cross-sectional view of the FIG. 23, along line 26-26;

FIG. 27 is a cross-sectional view of the FIG. 23, along line 27-27;

FIG. 28 is a cross-sectional view of the FIG. 23, along line 28-28;

FIG. 29 is a schematic depiction of the effect of the ammunition guidesurfaces and multifaceted block on the position of an ammunitioncartridge as a bolt carrier of an AR-15 type rifle engages an ammunitioncartridge stored in the magazine of FIG. 1;

FIG. 30 is a schematic depiction of the effect of the ammunition guidesurfaces and multifaceted block on the position of the ammunitioncartridges as a bolt carrier of an AR-15 type rifle feeds the engagedammunition cartridge into the barrel extension of the rifle;

FIG. 31 is a schematic depiction of the effect of the ammunition guidesurfaces and multifaceted block on the position of the ammunitioncartridges as a bolt carrier of an AR-15 type rifle feeds the engagedammunition cartridge into the chamber of the rifle;

FIG. 32 is a schematic depiction of the effect of the ammunition guidesurfaces and multifaceted block on the position of the ammunitioncartridges as a bolt carrier of an AR-15 type rifle locks the engagedammunition cartridge into the chamber of the rifle;

FIG. 33 is a schematic depiction of the effect of the ammunition guidesurfaces and multifaceted block on the position of the ammunitioncartridges as a bolt carrier of an AR-15 type rifle recoils after firingand cocking the trigger;

FIG. 34 is a schematic depiction of the interaction between the magazineof FIG. 1 and the AR-15 type rifle, as the tip of the resilient tab onthe magazine follower pushes the bolt catch upward to stop forwardtravel of the bolt carrier;

FIG. 35 is a schematic depiction of the right side view of the magazineof FIG. 1 loaded with 30 ammunition cartridges, as indicated by amarking on the port side wing which is visible through a window in themagazine casing;

FIG. 36A shows a spring wire with a round (or circular) cross section;

FIG. 36B shows a shaped spring wire with an oval cross section;

FIG. 36C shows a shaped spring wire with a square cross section;

FIG. 36D shows a shaped spring wire with a rectangle cross section;

FIG. 36E shows a shaped spring wire with a trapezoid cross section;

FIG. 36F shows a shaped spring wire with a sharp triangle cross section;

FIG. 36G shows a shaped spring wire with a wedge cross section;

FIG. 36H shows a shaped spring wire with an equilateral triangle crosssection;

FIG. 36I shows a shaped spring wire with a pie cross section;

FIG. 36J shows a shaped spring wire with a half round (or D) crosssection;

FIG. 36K shows a stranded spring wire in cross section, the strandedspring wire being formed from three strands; and

FIG. 36L shows a stranded spring wire in cross section, the strandedspring wire being formed from seven strands.

DESCRIPTION

FIGS. 1 and 2 show an exemplary embodiment of an ammunition magazine 10of the present invention. As shown in FIG. 6, the magazine may include ahousing 12, a follower 14, a spring 16, a floor plate 18 and a base 20.Referring to FIG. 3, the magazine 10 may be configured and dimensionedfor use with an AR-15 rifle (or M-4 carbine) 22. Referring to FIG. 4,the magazine 10 may be used to store and feed up to thirty ammunitioncartridges 24. Although the exemplary embodiment of the magazine isconfigured and dimensioned to store and feed NATO 5.56 mm cartridges or.223 Remington cartridges, other types of suitable ammunition cartridgesmay be used.

As shown in FIG. 1, the magazine may include an upper portion 26 whichinterfaces with the rifle and a lower portion 28 which is primarilyhandled by the user. The upper portion of the magazine may include apair of magazine feed lips 30, 32. The magazine lips may be disposed ina contra-lateral configuration. The magazine lips may be configured anddimensioned to interface with a portion of a rifle bolt. Additionally,the upper portion may include a projection 34 that is configured anddimensioned to interlock with a magazine catch on the rifle. Themagazine catch may interlock with the projection to selectively securethe magazine within the rifle.

The lower portion 28 of the magazine may include a fore grip 36 and arear grip 38. The fore grip and/or the rear grip may include a region ofraised features 40. The raised features may include a plurality ofgeometric shapes. For example, the fore grip may include a plurality ofgenerally rectangular shaped projections 42 and the rear grip mayinclude a plurality of generally triangular shaped projections 44. Theprojections may be arranged in one or more patterns to improve theability of a user to hold and handle the magazine. Additionally, thelower portion of the magazine may include a window 46. The window may bedisposed between the fore grip and the rear grip. The window may providea user with a view of the magazine interior. For example, the window mayprovide a view of cartridges that are stored in the magazine.

The magazine may include indicia 48. The indicia may be associated withthe window and may indicate the number of ammunition cartridges whichare stored in the magazine. For example, the indicia may include tickmarks and numbers. For instance, tick marks may be spaced on themagazine to designate storage intervals of five ammunition cartridges.Numerals may be placed by some or all of the tick marks to indicate thenumber of ammunition cartridges in the magazine. In FIG. 1, numerals areshown next to tick marks designating the 10, 20, and 30 ammunitioncartridge storage interval marks.

As shown in FIGS. 1 and 6, the magazine housing 12 may include a frontsidewall 50, a rear side wall 52, a port side wall 54 and a starboardsidewall 56. In the exemplary embodiment, the front side wall mayconform to a first imaginary curve having a radius of approximately 750mm, and the rear side wall may conform to a second imaginary curvehaving a radius of approximately 810 mm. The first center point and thesecond center point may define a vertical axis. The first center pointmay be situated above the second center point. For example, the centerof the first imaginary curve may be disposed above the center of thesecond imaginary curve such that the internal distance between the frontside wall and the rear side wall at the top of the magazine may beapproximately 60.4 mm and the internal distance between the front sidewall 50 and the rear sidewall 52 at the bottom of the casing may beapproximately 61.3 mm. Accordingly, the distance separating the frontside wall and the rear sidewall at the top of the housing isapproximately 1 mm less than the distance separating the front sidewalland the rear sidewall at the bottom of the housing.

Referring to FIG. 5, the housing 12 may include a front sill 62, a rearsill 64, a starboard side magazine feed lip 30, a port side magazinefeed lip 32, and internal guide surfaces 66, 68 for the follower andammunition cartridges.

As shown in FIGS. 19 and 21, the starboard side wall 30 may includeguide surfaces 66, 68 for the follower and ammunition cartridges. Thefollower guide surfaces 66 may include a generally planar surface 70, aconcave surface 72 abutting the generally planar surface, and a convexsurface 74 abutting the concave surface. These surfaces may form abumper track 76, which is configured and dimensioned to receive aportion of the follower. Accordingly, the starboard sidewall may includea bumper track 76 having a cross-sectional profile that includes agenerally planar segment, a concave segment and a convex segment.

The ammunition cartridge guide surfaces 68 may include a projectileguide surface 78, a cartridge neck guide surface 80, and a cartridgeshoulder guide surface 82. These surfaces 78, 80, 82 may form anammunition cartridge track 84, which is configured and dimensioned tosupport a particular type of ammunition cartridge, such as a 5.56×45 mmNATO round. Accordingly, the starboard sidewall may include anammunition cartridge track having a cross-sectional profile which, inpart, resembles the contour of an ammunition cartridge.

The guide surfaces further may include a multi-faceted block 86, whichprojects from the starboard sidewall 56 near the top of the housing. Themulti-faceted block 86 may intersect the follower and ammunitioncartridge guide surfaces and may include: a tapered, concave uppersurface 88; an angled and tapered side surface 90; an angled sub-sidesurface 92; and an angled and tapered rear surface 94. The multi-facetedblock further may include a lower surface 96.

The tapered concave upper surface 88 may be configured and dimensionedto form a ramp for directing a forward moving ammunition cartridgeupward and over the front sill 62 of the housing. The angled and taperedside surface 90 may be configured and dimensioned to push the projectileof an ammunition cartridge toward the center of the housing as thecartridge moves up the face of the angled and tapered side surface 90.

The angled sub-surface 92 may form a ramp which connects the angled andtapered side surface 90 and the cartridge neck guide surface 80. Theangled sub-side surface 92 may be configured and dimensioned to push thecartridge neck of an ammunition cartridge toward the center of thehousing as the cartridge moves up the face of the angled sub-sidesurface.

The angled and tapered rear surface 94 may form a ramp which connectsthe tapered concave upper surface 88 and the ammunition cartridgeshoulder guide surface 82. The angled and tapered rear surface 94 may beconfigured and dimensioned to push the shoulder of an ammunitioncartridge toward the rear of the housing as the cartridge moves up theface of the angled and tapered rear surface.

The lower surface 96 may extend from the angled and tapered side surface90 to the bumper track 76 such that the lower surface forms an end wallfor the track. The end wall may be perpendicular to the follower guidesurfaces 70, 72, 74 which may form the track.

The starboard side magazine feed lip 30 may include internal guidesurfaces 68 for stabilizing or directing movement of the ammunitioncartridge body. For example, a series of curved surfaces may connect thestarboard side wall to the interior side walls of the magazine feed lip.As shown in FIGS. 19 and 21, a rear guide surface 98, an intermediateguide surface 100, and a front guide surface 102 may be configured anddimensioned to direct the ammunition cartridge body upward and inward asthe ammunition cartridge moves forward against the interior guidesurfaces.

The features described above in connection with the starboard side wall56 may be found on the port side wall 54, as well. In general, theinternal configuration of the port sidewall may be a mirror image of thestarboard side wall. The starboard sidewall features described in FIGS.7-9 and 19-21, therefore, may have complimentary counterpart features onthe port sidewall. Hence, the internal guide structures within thehousing may be symmetrical about a central plane 104 that bisects thefront sidewall and the rear sidewall of the housing, as shown in FIG.20. These structures, which are identified with common reference elementnumbers, may include the follower guide surfaces 76, the ammunitioncartridge guide surfaces 84, the multi-faceted block surfaces 90, 92,64, 96 and the feed lip guide surfaces 98, 100, 102.

Referring to FIGS. 7 and 17, the bottom of the housing 12 may include aflange 106. The flange may extend around the circumference of thehousing. The housing may further include a groove 108 above the flange.The groove 108 may extend around three sides of the housing and maywiden toward the ends.

Referring to FIG. 11, the follower 14 may include a front end 110, arear end 112, an upper surface 114, a lower surface 116, and fourstabilizing structures. The four stabilizing structures may include afront bumper 118, a rear bumper 120, a port side wing 122 and astarboard side wing 124.

The upper surface 114 of the follower 14 includes a base portion 126, anintermediate portion 128, and a tapered front portion 130. The baseportion 126 includes a generally smooth and flat area on the port sideand a raised cartridge spacer 132 on the starboard side. The cartridgespacer 132 includes a generally flat rear portion 134, a concave shapedmiddle portion (or crown) 136, and a sloped front portion 138. Thecartridge spacer may include a starboard escarpment 140 and a portescarpment 142. The intermediate portion 128 abuts the base portion 126.The intermediate portion 128 may be generally flat and smooth. Theintermediate portion may connect the base portion 126 with the fronttapered portion 130. The front tapered portion 130 may narrow and slopedownward to the front bumper 118.

The follower may include an upper surface 114, a lower surface 116, anda side surface 144 extending between the upper surface and a lowersurface. The follower may include a front bumper 118 that is disposedbelow the front tapered portion 130 of the upper surface. Referring toFIG. 14, the follower 14 may include a port side bumper 146 and astarboard side bumper 148. The port side bumper 146 may extend laterallyand curve backward from the port side of the front bumper 118; thestarboard side bumper 148 may extend laterally and curve backward fromthe starboard side of the front bumper 118. The interior surface of thefront bumper, port side bumper, and starboard side bumper may form asmooth curved surface 150. The curved surface may form a front shroudfor the magazine spring.

The rear bumper 120 may include a stem 152 which extends downward fromthe rear end of the upper surface of the follower. The stem may includea resilient tab 154. The resilient tab 154 may be integrally connectedto the base of the stem 152. The resilient tab may be configured anddimensioned to slide in a channel 156 on the rear side of the housing.The resilient tab may be flexible, and the gap between the resilient taband the stem may be sized to allow the resilient tab to be pressedagainst the stem in a compressed configuration, as well as spaced fromthe stem in an extended configuration. The tip 158 of the resilient tabmay form a ledge which moves the bolt catch of a firearm after the lastammunition cartridge has been removed from the magazine. The interiorsurface of the stem may include a curved surface 160 which forms a rearshroud for a portion of the magazine spring.

The port side wing 122 may extend downward and away from the port sidesurface of the follower. The port side wing 122 may be generallyrectangular in shape. The port side wing may be relatively thin due tothe confined space requirements of the magazine interior. The port sidewing may be flexible and resilient. The starboard side wing 124 may belocated opposite the port side wing 122 on the starboard side surface ofthe follower. The starboard side wing 124 may otherwise be similar inconstruction and resilience to its counterpart. The side wings of thefollower may be visible in the windows 46 of the magazine. The bottomedge 162 or a marking on the side wings may cooperate with indiciaaround the window to indicate the number of ammunition cartridges in themagazine.

The lower surface 116 of the follower 14 may include an axial shank 164,a leading cross shank 166, and a trailing cross shank 168. The leadingcross shank may include a ledge 170 beneath the lower surface of thefollower. The ledge 170 and the lower surface 116 of the follower 14 maycooperate to form a seat or spring attachment location for the magazinespring. The leading cross shank 166 and the trailing cross shank 168,further may be configured and dimensioned to provide internal supportfor the magazine spring 16.

Referring to FIGS. 12, 22A, 22B, 22C and 22D, the magazine spring 16 maybe a compression spring. In the exemplary embodiment, the magazinespring may be formed by a round wire coil that includes a small curve172 separated from a larger curve 174 by a straight length 176. As shownin FIG. 22A, the wire may have a diameter D1 of approximately 1.5 mm. Asshown in FIG. 22D, the radius of the small curve (or small radius) R1may be approximately 6.5 mm, and the radius of the larger curve (orlarge radius) R2 may be approximately 8.1 mm. The length of the coilmeasured from the end of the small curve to the end of the largerdiameter curve (or maximum outer dimension of wire coil) L3 may beapproximately 49.5 mm.

Referring back to FIG. 22A, the wire may be right hand wound and have apitch L2 of approximately 19 mm. The ends 240, 242 of the magazinespring may be squared. As shown in FIG. 22E, one end of the magazinespring may terminate with an end segment having a length L4 ofapproximately 22.8 mm. This end 240 may be configured and dimensioned toconnect with the floor plate 18, as shown in FIGS. 15-16 and describedbelow.

Referring to FIG. 22F, the other end of the spring 242 may terminatewith a generally L-shaped segment having a dimension L5 of approximately5.0 mm and a length L6 of approximately 37.5 mm. The other end 242 maybe configured and dimensioned to connect to the follower 14, as shown inFIGS. 12-14 and described below.

In the embodiment shown in FIGS. 22A-C, the magazine spring may includeapproximately 15 total coils. The magazine spring may have a free lengthof approximately 277 mm, and may possess a preloaded force ofapproximately 15 N (Newton) for a reference length of 180 mm. The solidheight of the coil (or fully closed length) may be approximately 25.5mm. The wire may be music wire as specified by ASTM A228.

A summary of a preferred magazine spring design for the 30 roundmagazine of FIG. 1 is presented in Table 1.

TABLE 1 Magazine Spring Design for a 30 Round Capacity MagazinePreferred Preferred Most Variable/ Upper Lower Preferred Parameter UnitsValue Value Value Outer Dimension (Wire) D1 (mm) — — 1.5 Free Length L1(mm) — — 277.0 Pitch L2 (mm) — — 19 Outer Dimension (Coil) L3 (mm) 49.849.2 49.5 Length of Bottom End L4 (mm) 23.1 22.5 22.8 Length of OffsetL5 (mm) 5.3 4.7 5.0 Length of Top End L6 (mm) 37.8 37.2 37.5 SmallRadius R1 (mm) 6.8 6.2 6.5 Large Radius R2 (mm) 8.4 7.8 8.1 OffsetRadius R3 (mm) 2.5 1.9 2.2 Reference Length RL (mm) — — 180 PreloadedForce PF (N) — — 15 Solid Height LFC (mm) — — 25.5 (or Full CloseLength) Notes: (a) Type of ammunition cartridge: 5.56 × 45 mm NATO or.223 Remington. (b) Type of wire: round wire per ASTM A228.

The general spring configuration of FIGS. 22A-F may be adapted for usein other magazines. For example, the magazine spring may be designed foran ammunition magazine that stores up to ten 5.56×45 mm ammunitioncartridges. In one embodiment, a ten round capacity magazine may includea shortened and straighter casing, but which otherwise maintainsfeatures and components of the magazine of FIG. 1. In another example,the magazine spring may be adapted for use in an ammunition magazinecartridge that stores up to twenty 5.56×45 mm ammunition cartridges. Inyet another example, the magazine spring may be adapted for use in anammunition magazine cartridge that stores up to thirty five, forty five,or fifty 5.56×45 mm ammunition cartridges.

Table 2 presents a preferred magazine spring design for an ammunitionmagazine that may store and feed an AR15 type rifle with up to ten5.56×45 mm ammunition cartridges.

TABLE 2 Magazine Spring Design for a 10 Round Capacity MagazinePreferred Preferred Most Variable/ Upper Lower Preferred Parameter UnitsValue Value Value Outer Dimension D1 (mm) — — 1.5 (Round Wire) FreeLength L1 (mm) — — 180.5 Pitch L2 (mm) — — 19 Outer Dimension (Coil) L3(mm) 49.8 49.2 49.5 Length of Bottom End L4 (mm) 23.4 22.8 23.1 Lengthof Offset L5 (mm) 5.3 4.7 5.0 Length of Top End L6 (mm) 37.8 37.2 37.5Small Radius R1 (mm) 6.4 5.8 6.1 Large Radius R2 (mm) 8.4 7.8 8.1 OffsetRadius R3 (mm) 2.5 1.9 2.2 Reference Length RL (mm) — — 75.0 PreloadedForce PF (N) — — 15 Solid Height LFC (mm) — — 20.0 (or Full CloseLength) Notes: (a) Type of ammunition cartridge: 5.56 × 45 mm NATO or.223 Remington. (b) Type of wire: round wire per ASTM A228.

The foregoing spring designs are believed to have important operationalbenefits, such as providing greater spring force at the front of thefollower due to the smaller radius at the front end of the coil. Largerspring forces at the front end of the coil may promote reliable feedingof ammunition cartridges from the magazine by overcoming any added localresistance at the front of the casing that may be generated by theinteraction of the ammunition cartridges and multi-faceted block.Moreover, larger spring forces at the front end of the coil may providefor a firmer squeeze of the ammunition cartridges near the top of themagazine. This may advantageously position and secure the ammunitioncartridges near the top of the magazine, as described in more detailbelow. Also, larger spring forces at the front end of the coil maypromote reliable feeding of ammunition cartridges from the magazine asthe quantity of stored ammunition cartridges run low because theattitude of the front end of the follower may be more likely to remainin a neutral or elevated position as the magazine spring approaches thelimits of its working length.

Accordingly, the benefits of the foregoing spring designs may becaptured and extended by maintaining the general configuration of themagazine spring designs of Table 1 and Table 2 by examining therelationship between the smaller radius and larger radius of the wirecoil. This relationship may be described, in part, by a “coil ratio” (orCR), which may be calculated by dividing the larger radius of the wirecoil by the smaller radius of the wire coil. For example, the coil ratioof the most preferred magazine spring design presented in Table 1 (wherethe smaller radius is 6.5 mm and the larger radius is 8.1 mm) isapproximately equal to 1.25 (i.e., 8.1/6.5). Likewise, the coil ratio ofthe most preferred magazine spring design presented in Table 2 (wherethe smaller radius is 6.1 mm and the larger radius is 8.1 mm) isapproximately equal to 1.33 (i.e., 8.1/6.1).

Table 3 presents coil ratio calculation results for the preferred andmost preferred values of the spring designs of Table 1 and Table 2.

TABLE 3 Coil Ratios (CRs) for the Spring Designs of Tables 1 and 2 R2(mm) 7.8 7.9 8.0 8.1 8.2 8.3 8.4 R1 (mm) 5.8 1.34 1.36 1.38 1.40 1.411.43 1.45 5.9 1.32 1.34 1.36 1.37 1.39 1.41 1.42 6.0 1.30 1.32 1.33 1.351.37 1.38 1.40 6.1 1.28 1.30 1.31 1.33 1.34 1.36 1.38 6.2 1.26 1.27 1.291.31 1.32 1.34 1.35 6.3 1.24 1.25 1.27 1.29 1.30 1.32 1.33 6.4 1.22 1.231.25 1.27 1.28 1.30 1.31 6.5 1.20 1.22 1.23 1.25 1.26 1.28 1.29 6.6 1.181.20 1.21 1.23 1.24 1.26 1.27 6.7 1.16 1.18 1.19 1.21 1.22 1.24 1.25 6.81.15 1.16 1.18 1.19 1.21 1.22 1.24

As shown in Table 3, the CR values for the preferred Small Radius andLarge Radius values of the spring design of Table 1 range fromapproximately 1.15 to approximately 1.35. The CR value for the mostpreferred Small Radius and Large Radius values of the spring design ofTable 1 is approximately 1.25. By comparison, the CR values for thepreferred Small Radius and Large Radius values of the spring design ofTable 2 range from approximately 1.22 to approximately 1.45. The CRvalue for the most preferred Small Radius and Large Radius values of thespring design of Table 2 is approximately 1.33.

The combined range of CR values for the preferred Small Radius and LargeRadius values of the spring designs of Table 1 and Table 2 range fromapproximately 1.15 to approximately 1.45. These CR values reflectmagazine spring coil configurations that provide suitable operation oftwo ammunition magazines constructed in accordance with aspects of thepresent invention.

The shared range of CR values for the spring designs of Table 1 andTable 2 range from approximately 1.22 to approximately 1.35. The CRvalues for the most preferred Small Radius and Large Radius values ofthe spring designs of Table 1 and Table 2 are contained within theshared range of CR values These CR values reflect magazine spring coilconfigurations that provide enhanced operation of two ammunitionmagazines constructed in accordance with aspects of the presentinvention.

Magazine springs for small arms weapons, however, generally may have asmall radius R1 that ranges from approximately 3 mm to approximately 7mm and a large radius R2 that ranges from approximately 5 mm toapproximately 9 mm, as long as the larger radius R2 is greater than thesmall radius R1. Hence, CR values for a magazine spring for many smallarms weapons generally may be greater than 1 and less than approximately3.

Moreover, in view of foregoing, CR values for a magazine spring for asmall arms weapon preferably may be at least 1.05. More preferably, CRvalues a magazine spring for a small arms weapon may range fromapproximately 1.10 to approximately 1.50. Most preferably, CR values fora magazine spring for a small arms weapon may range from approximately1.20 to approximately 1.35. In the embodiment of the magazine springdesign of Table 1, the optimum RV value is approximately 1.25. In theembodiment of the magazine spring design of Table 2, the optimum RVvalue is approximately 1.32.

Although the spring designs of Table 1 and Table 2 are believed to haveimportant operational benefits, other wire types, dimensions, orconfigurations may be used provided the alternate magazine spring designprovides reliable operation of the magazine.

Referring to FIGS. 36A-L, the magazine spring may be formed from round,shaped, or stranded wire. Round wire 248 may have a circular crosssection 250 (FIG. 36A). Typically, round wire diameters may range from0.10 mm to 16 mm.

Referring to FIGS. 36B-J, shaped wire 252 may be defined as wire with across-sectional shape other than round, which may be produced by coldrolling. Typical shapes may include oval 254 (FIG. 36B), square 256(FIG. 36C), rectangular 258 (FIG. 36B), trapezoid (or “keystone”) 260(FIG. 36E), sharp triangle 262 (FIG. 36F), wedge 264 (FIG. 36G),equilateral triangle 266 (FIG. 36H), pie 268 (FIG. 36I), and half round270 (FIG. 36J). The solid height of a shaped wire may be less than thatof a similar round wire spring. Also, using chrome silicon shaped wirerather than traditional carbon steel material may produce a spring thatcan withstand additional shock and heat.

Referring to FIGS. 36K and 36L, stranded wire 272 may be formed fromseveral strands of wire (e.g., three to seven strands of wire) that aremachine-twisted or woven around each other 274 (FIG. 36K), or around onewire that serves as a core 276 (FIG. 36J), to form a single strand. Thestranded wire may be made of music wire, rocket wire or other suitablematerial. Stranded wire springs may be well suited to repetitive impactloading conditions and may provide a long life cycle for the spring.

Spring materials may be high strength alloys having a Young's Modulus,E, ranging from approximately 190×10³ MPa at standard temperature andpressure. Suitable spring wire may include carbon steel wire, includingwithout limitation music wire. Preferably, the music wire may conformwith ASTM A228. Alloy steel wire, such as chrome silicon wire, as wellas other materials may be used.

Additionally, the magazine spring of FIG. 22A may be designed for usewith ammunition magazines that store 5.45×51 mm ammunition cartridges,5.45×39 mm ammunition cartridges, 7.62×54 mm ammunition cartridges;7.62×51 mm ammunition cartridges, 7.62×39 mm ammunition cartridges; .308Winchester ammunition cartridges; and other ammunition cartridges. Thecasing and other magazine components may need to be adjusted for theseapplications as well. For instance, the magazine casing may need to bemodified for weapon compatibility. For example, the magazine of FIG. 1may be tailored for compatibility with the following non-limiting listof small arms weapons: AR-15, M16, M4, M249, LSAT, HK416, AK-47, andNegev LMG.

Referring to FIGS. 7 and 8, the magazine spring 16 may be secured to thefollower at the seat 178 formed by the ledge 170 on the leading crossshank and the opposing lower surface 116 of the follower.

Referring to FIG. 15, the floor plate 18 may include an upper surface180 and lower surface 182. The upper surface of the base plate mayinclude an axial wall 184. The axial wall 184 may include an upper side186 that is spaced from the upper surface of the floor plate. The upperside 186 of the axial wall may have a length that is shorter than theaxial shank 164 of the follower. The axial wall may include a front side188 that extends from the front of the top surface to the upper surface180 of the floor plate. Additionally, the axial wall may include a rearside 190 that extends from the rear of the top surface to the uppersurface 180 of the floor plate. The front side 188 of the axial wall mayinclude a notch 192 near the upper surface 180 of the floor plate. Thefront notch 192 may be configured and dimensioned to receive and securea spring wire. The rear side 190 of the axial wall may include a notch194 near the upper surface of the floor plate. The rear notch 194 may beconfigured and dimensioned to receive and secure a spring wire. Theaxial wall may include side buttresses 196, 198. The side buttresses mayeach include a side notch 200, 202 for receiving and securing themagazine spring 16. As shown in FIGS. 7 and 9, the lower end of themagazine spring 16 may be secured to the floor plate at four magazinespring attachment points. Two attachment points may be notches 192, 194near the base of the axial wall, and two attachment points may benotches 200, 202 near the base of each buttress.

Referring to FIGS. 9, 16, and 17, the lower side 182 of the floor plate18 may include a planar surface 204 and a raised area 206 that extendsaway from the planar surface. The raised area 206 may include a flatupper surface 208 and a sidewall 210 extending from the upper surface tothe lower side of the floor plate. The raised area may be formed in abutton shape. The upper surface of the raised area may include a concavesurface 212. The upper side 180 of the floor plate and the lower side182 of the floor plate may have different lengths. For example, thelength of the upper side may be greater than the length of the lowerside. The rear end of the floor plate may taper from a longer uppersurface to a shorter lower surface to form a projection 214.

Referring to FIG. 18, the base may include an elongated plate 216. Theelongated plate may include a front side 218, a rear side 220, andlateral sides 222 between the front and rear sides. The base may furtherinclude a side wall 224. The side wall 224 may surround the elongatedplate on three sides. For example, the side wall may surround theelongated plate on the front and lateral side. Referring to FIGS. 16 and17, the side wall may include a groove 226. The groove 226 may beconfigured and dimensioned to slide on to the housing flange 106. Eachend of the side wall may include an attachment structure 228, such as alever, which is configured and dimensioned to form a mechanical jointwith the housing. For example, the lever 228 and housing ledge 106 mayform a snap-fitting. Preferably, the snap-fitting is a releasable joint.

Referring to FIGS. 17 and 18, the elongated plate 216 may include aninterior surface 230 and an exterior surface 232. The interior surface230 may include a notch 234. The notch 234 may include an end wall 236.The end wall may include an opening 238 which extends to the exteriorsurface 232 of the plate. The notch 234 may be configured anddimensioned to mate with the raised area on the floor plate.

Referring to FIG. 7, the magazine may have an unloaded configuration inwhich the follower 14 may be disposed in the housing 12 such that thefront bumper 118 faces the front wall of the housing, the lower portionof the resilient tab 152 may be in the channel 156 on the rear side 52of the housing, and the tip of the resilient tab 158 may be positionedabove the rear sill 64. Additionally, the starboard side bumper 148 maypress against the lower surface 96 of the multi-faceted block on thestarboard side 56 of the housing, and the port side bumper 146 may pressagainst the lower surface 96 of the multi-faceted block on the port sideof the housing. Moreover, the spacer 132 may press against the starboardside magazine feed lip 30. The magazine spring 16 may exert a force ofapproximately 15 N on the follower 14. The magazine spring 16 also mayexert an opposite force of approximately 15 N on the floor plate 18. Theraised area 206 on the lower surface of the floor plate may be disposedin the notch 234 on the interior surface of the base plate, and the baseplate groove 226 may be interlocked with the housing flange 106.

Referring to FIG. 12, the front bumper 118 may be spaced from the frontwall 50 of the housing, the resilient tab 154 may be disposed in thechannel 156 on the rear wall of the housing, and the top of the magazinespring 16 may be secured to the leading cross shank 166 and containedwithin the front shroud 150, rear shroud 160, starboard side wing 124,and port side wing 122.

Referring to FIG. 13, the starboard side bumper 148 and port side bumper146 are disposed in the starboard side bumper track 76 and port sidebumper track 76, respectively. The stem 152 of the resilient member maybe disposed in the channel 156 on the rear sidewall 52 of the housing,and the rear bumper 120 may be disposed against the rear side wall 52 ofthe housing. The top of the magazine spring may be secured to theleading cross shank 166 and contained within the front shroud 150, rearshroud 160, starboard side wing 124, and port side wing 122.

Referring to FIGS. 8, 9, and 10, ammunition cartridges 24 may be loadedinto the magazine 10. As shown in FIG. 10, the ammunition cartridges 24may be stacked in two columns on the follower 14. The port side row ofammunition cartridges may generally rest on the upper surface 114 andthe starboard side row of ammunition cartridges rest on the cartridgespacer 132. The cartridge 24 nearest the top of the magazine is retainedby the magazine feed lip 30 on the starboard side of the housing.Referring to FIG. 8, the starboard bumper 148 is disposed in thestarboard bumper track 76 and the starboard facing sides of theammunition cartridges are pressed against ammunition cartridge guidesurfaces 78, 80, 82. Referring to FIG. 9, as the magazine reaches fullcapacity the follower 14 approaches the base 20 of the magazine. Whenthe magazine is fully loaded with ammunition cartridges (i.e., in thefully loaded configuration), the axial shank 164 or cross shanks 166,168 of the follower rest on top of the axial wall 186. This blocks overcompression of the magazine spring 16 because the solid height of thespring is less than the distance from the spring attachment points 192,194,200, 202 on the upper surface of the floor plate to the springattachment point 170 under the lower surface of the follower. In anotherembodiment, the front bumper 118 and rear bumper 120 of the follower 14also rest on the floor plate 18 in the fully loaded configuration. Thebottom ammunition cartridge has been removed from FIGS. 8 and 9 togenerally illustrate the relation between the features of the ammunitioncartridges and the ammunition cartridge guide surfaces.

The magazine components (other than the spring) may be formed from apolymer material. For example, the housing may be formed from aninjection molded polymer (e.g., polyamide, polyphthalamide (PPA), orpoly aryl ether ketone (PEK)). Preferably, the housing may be formedfrom polyamide nylon 6,6. Additionally, the polymer matrix may includereinforcement fibers (e.g., carbon-fiber or glass-fiber). Althoughpolymer or reinforced polymer materials may be preferred for forming themagazine components, other materials that are sufficiently strong anddurable may be used. For example, the magazine components may bemanufactured from aircraft quality aluminum, titanium, steel or otheralloys. Also, magazine components may be formed by over molding a secondmaterial over a base part. For example, an elastomer (e.g., rubber), maybe over molded on to a component formed from carbon-fiber reinforcedpolymer. Accordingly, the fore grip and rear grip portions of thehousing may be formed from rubber that is molded on top of acarbon-fiber reinforced polymer material.

Referring to FIG. 35, the follower 14 may include one or more markings278 (e.g., a line, an arrow, dot, triangle, visual target, orilluminated feature) which are visible through one (or both) window(s)46 in the magazine casing 12. The marking(s) 278 may cooperate with theindicia 48 on the sides of the window 46 to indicate the number ofammunition cartridges 24 in the magazine. For example, the marking 278may be a line that points to a tick mark 48 a along a numerical scalethat is positioned on the side of the window to provide a visualindication of the number of ammunition cartridges 24 in the magazine.

In use, a loaded magazine 10 (FIG. 35) may be inserted into the magazinewell 280 of a small arms weapon 22 such as an M4, M-16, or AR-15 typefirearm (see e.g., FIG. 3). As the weapon 22 is charged (FIGS. 29-31),the bolt carrier 282 may advance between the magazine feed lips and thebolt 284 may push the uppermost ammunition cartridge 24 forward, inward,and upward over the front sill 62 of the magazine toward the barrelextension 290 and firearm chamber 286. As described below, the taperedconcave upper surface 88 of the multi-faceted block and adjacent frontsidewall of the magazine, as well as the guide surfaces 98, 100, 102 onthe magazine feed lips 30, 32 are configured to stabilize and direct thetransfer of ammunition cartridges to the firearm chamber (FIGS. 23-28).

As the uppermost ammunition cartridge is transferred from the magazine,the magazine spring pushes the follower upward to position the nextammunition cartridge for feeding (FIG. 32). As each ammunition cartridgeadvances up the magazine, the ammunition cartridge encounters the angledand tapered rear surface 94 that is configured to push the ammunitioncartridges backward (e.g., FIGS. 23, 25 and 29). Shortly thereafter, theammunition cartridge 24 will encounter the angled subsurface 92, whichis configured to push the front of the ammunition cartridge inward(FIGS. 23, 26 and 27). The tip of the ammunition cartridge may moveinward by a distance L7 of approximately 1 mm (FIG. 27).

As the ammunition cartridge 24 rises above the edge of the angled andtapered rear surface 94, the pressure from the multi-faceted block 86 isremoved (FIGS. 23 and 28) and the front tip of the ammunition cartridgemay shift outward by approximately 1 mm, and settle on top of thetapered concave upper surface 88. Additionally, the ammunition cartridgemay shift forward, and move upward and inward under the direction of thetapered concave upper surface 88, adjacent front sidewall of themagazine, and adjacent ammunition cartridges or follower to an improvedposition for feeding into the barrel extension 290 and chamber 286(FIGS. 23, 24, 28 and 29). After the final ammunition cartridge in themagazine has been fired 24 f, the resilient tab 158 may rise above therear sill 64 to move the bolt catch 288 in position to block forwardtravel of the bolt 284 (FIG. 34).

As shown in FIG. 24, the ammunition cartridges 24 b, 24 c near theuppermost ammunition cartridge 24 a may be increasingly compressedbetween the lower stack of ammunition cartridges and/or the follower 14,the multi-faceted block 86 and the magazine casing side walls 52, 54.Squeezing the ammunition cartridges 24 b, 24 c, 24 d, 24 e and 24 f inthis manner may provide a compact arrangement which forms a stable,secure mass that acts as another guide surface for the uppermostammunition cartridge 24 a. Thus, the compact arrangement of ammunitioncartridges may provide a stable bottom guide for the upper mostammunition cartridge. Also, pressure applied on the uppermost ammunitioncartridge 24 a by the adjacent ammunition cartridges 24 b, 24 c may helpdrive the uppermost ammunition cartridge upward as it is pushed forwardby the bolt.

A compact, stable, and secure arrangement of ammunition cartridges nearthe top of the magazine may prevent (or limit) uncontrolled movement orjostling of the ammunition cartridges, which may result from firingrecoil, recoil travel of the bolt assembly, or external impacts to themagazine or weapon. This may reduce the likelihood of a misfeed orjamming of the weapon.

The magazine spring of FIG. 22A may facilitate reliable feeding of theammunition cartridges to the firearm chamber because the relativelystronger spring forces applied to the front of the follower 14 may helpthe ammunition cartridges smoothly overcome the restriction caused bythe multi-faceted block. Relatively stronger spring forces at the frontof the follower may compact the nearby ammunition cartridges against thecasing side walls to form a more stable and secure mass. Relativelystronger spring forces applied to the front of the follower also mayhelp maintain the front of the follower in a favorable position fortraveling through the magazine and feeding the uppermost cartridge tothe weapon. Further relatively stronger spring forces applied to thefront of the follower may better resist impacts from firing recoil andreturn travel of the bolt carrier. The resilient follower wings 122, 124and resilient rear tab 154 may provide a degree of freedom of movementand resistance within the magazine casing to further accommodate impactsand promote proper positioning of the ammunition cartridges for feedingto the firearm.

While it has been illustrated and described what at present areconsidered to be a preferred embodiment of the present invention, itwill be understood by those skilled in the art that various changes andmodifications may be made, and equivalents may be substituted forelements thereof without departing from the true scope of the invention.For example, the magazine may be formed with a smaller ammunitioncapacity or different spring design to accommodate different types ofammunition cartridges. Likewise, the configuration of the magazinecasing may be modified for compatibility with other small arms weapons.Additionally, features and/or elements from any embodiment may be usedsingly or in combination with other embodiments. Therefore, it isintended that this invention not be limited to the particularembodiments disclosed herein, but that the invention include allembodiments falling within the scope and the spirit of the presentinvention.

What is claimed is:
 1. A magazine for storing and feeding ammunitioncartridges to a small arms weapon comprising: a casing which comprisesan upper end and a lower end; a floor plate situated near the lower end;a follower adjacent the floor plate; and a magazine spring inside thecasing which comprises a first end connected to the follower, a secondend connected to the floor plate, and a plurality of coils, each of theplurality of coils including a first segment having a first radius, asecond segment having a first length adjoining the first segment, athird segment having a second radius adjoining the second segment, thesecond radius being greater than the first radius, and a fourth segmenthaving a second length adjoining the third segment, the second lengthbeing approximately equal to the first length, wherein the second radiusdivided by the first radius defines a coil ratio, and the coil ratio isbetween approximately 1.1 and approximately 1.5.
 2. The magazine ofclaim 1, wherein the magazine spring is preloaded for a force ofapproximately 15 N at a reference length of approximately 180 mm.
 3. Themagazine of claim 2, wherein the magazine spring has a solid height thatis less than or equal to approximately 25 mm.
 4. The magazine of claim1, wherein the second radius is approximately 8.1 mm.
 5. The magazine ofclaim 4, wherein the first radius is approximately 6.5 mm.
 6. Themagazine of claim 5, wherein the magazine spring is formed from a roundwire.
 7. The magazine of claim 6, wherein the round wire has an outerdiameter of approximately 1.5 mm.
 8. The magazine of claim 7, whereinthe round wire is music wire per ASTM A228.
 9. The magazine of claim 1,wherein the magazine spring is preloaded for a force of approximately 15N at a reference length of approximately 75 mm.
 10. The magazine ofclaim 9, wherein the magazine spring has a solid height less than orequal to approximately 20 mm.
 11. The magazine of claim 9, wherein thesecond radius is approximately 8.1 mm.
 12. The magazine of claim 11,wherein the first radius is approximately 6.1 mm.
 13. The magazine ofclaim 12, wherein the magazine spring is formed from a round wire. 14.The magazine of claim 13, wherein the round wire has an outer diameterof approximately 1.5 mm.
 15. The magazine of claim 14, wherein the roundwire is music wire per ASTM A228
 16. The magazine of claim 1, whereinthe casing is configured and dimensioned to store a plurality ofammunition cartridges for a small arms weapon.
 17. The magazine of claim16, wherein the casing is configured and dimensioned to store 30 orfewer ammunition cartridges.
 18. The magazine of claim 16, wherein thecasing is configured and dimensioned to store 10 or fewer ammunitioncartridges.
 19. The magazine of claim 16, wherein the casing isconfigured and dimensioned to store 5.56×45 mm NATO cartridges.
 20. Thespring of claim 16, wherein the casing is configured and dimensioned tostore .223 Remington cartridges.
 21. A magazine spring for an ammunitionmagazine for a small arms weapon comprising: a wire which comprises aplurality of coils, each of the plurality of coils including a firstsegment having a first radius, a second segment having a first lengthadjoining the first segment, a third segment having a second radiusadjoining the second segment, the second radius being greater than thefirst radius, and a fourth segment having a second length adjoining thethird segment, the second length being approximately equal to the firstlength, wherein the second radius divided by the first radius defines acoil ratio, and the coil ratio is at least about 1.05.
 22. The magazinespring of claim 21, wherein the coil ratio is less than about
 3. 23. Themagazine spring of claim 22, wherein the coil ratio ranges fromapproximately 1.10 to approximately 1.50.
 24. The magazine spring ofclaim 23, wherein the coil ratio ranges from approximately 1.20 toapproximately 1.35.
 25. The magazine spring of claim 24, wherein thecoil ratio is approximately 1.25.
 26. The magazine spring of claim 24,wherein the coil ratio is approximately 1.32.
 27. The spring of claim24, wherein the wire has a preloaded force of approximately 15 N for areference length that ranges from approximately 75 mm to approximately180 mm.
 28. The spring of claim 24, wherein the second radius is betweenapproximately 7.8 mm and 8.4 mm.
 29. The spring of claim 24, wherein thefirst radius is between approximately 5.8 mm and approximately 6.4 mm.30. The spring of claim 24, wherein the first radius is betweenapproximately 6.2 mm and approximately 6.4 mm.
 31. The spring of claim24, wherein each of the plurality of coils has a maximum outer dimensionbetween approximately 49.2 mm and approximately 49.8 mm.
 32. The springof claim 23, wherein the wire is a round wire.
 33. The spring of claim23, wherein the wire is stranded wire.
 34. The spring of claim 23,wherein the wire is shaped wire.
 35. The spring of claim 34, wherein theshaped wire is selected from the group consisting of square,rectangular, keystone, oval, elliptical, half round, or D-shaped. 36.The spring of claim 23, wherein the wire is carbon steel.
 37. The springof claim 36, wherein the wire is music wire.
 38. The spring of claim 23,wherein the wire is alloy steel.
 39. The spring of claim 38, wherein thewire is chrome silicon.
 40. A magazine for storing and feedingammunition cartridges to a small arms weapon comprising: a casing whichcomprises an upper end and a lower end; a floor plate situated near thelower end; a follower adjacent the floor plate; and a magazine spring ofclaim 21 inside the casing.